Fluid Drive Help

[bmcil26@aol.com]

Hello All, This is my first post and I thank you all for allowing me to enter this group. I am in dire need of a mechanic in the Chicago area that would know how to work on my 1949 Chrysler Windsor, specifically the fluid drive. I understand that when it is functioning properly, there is a "clunk" noise that occurs during gear change. I get a grinding noise just before it changes gears both in the low and high range. This only occurs when I release the gas to change to the next higher gear. but when I release my foot from the gas to stop. No noise. The noise sounds like a 3 speed manual when you change gears and let out the clutch before the gear is properly engaged. I have checked the fluid drive resevoirs under the front mats and both appear full. I also need electrical work Before I got the car a previous owner did a partial 6 to 12 volt conversion. All that works are the lights and the starter. The seller got the car that way so he could not give me any specifics on what had been done or how. My biggest problem is that I don't how to fix anything on the car, hence, I am looking for someone that I can trust to fix it for me locally. When I call dealers for help they basically laugh at my dilemna. This is such a beautiful car and I truly love it. Can anyone help me out on this? Thanking you all in advance.

Edited October 21, 2019 by bmcil26@aol.com

[casper50]

Where are you checking fluid level?  As far as I know there's only 1 place to check the level of a fluid drive.

[Andydodge]

Welcome aboard from Oz, Oztralia.........unfortunately the fluid Drive setup was not very common here in Oz and I certainly have not had any experience with it apart from 40 odd years ago when I owned a 1948 Chrysler Windsor, again an uncommon car here in Oz,we got Plymouths and Dodges with occaisonal DeSotos and our local variations of these 3 brands were essentially Plymouth based ........do you have a Workshop Manual and/or Owners Manual as I would strongly suggest obtaining these and reading cover to cover..............there are a couple of guys on here with Fluid Drive Chryslers, Dodges & DeSotos and they will be able to give sound and correct advice..........I'd actually change the title of this thread to something that includes "Fluid Drive"  so they will see it..........again, welcome aboard.......Andy Douglas  

Edited October 21, 2019 by Andydodge

[bmcil26@aol.com]

6 minutes ago, Andydodge said:

Welcome aboard from Oz, Oztralia.........unfortunately the fluid Drive setup was not very common here in Oz and I certainly have not had any experience with it apart from 40 odd years ago when I owned a 1948 Chrysler Windsor, again an uncommon car here in Oz,we got Plymouths and Dodges with occaisonal DeSotos and our local variations of these 3 brands were essentially Plymouth based ........do you have a Workshop Manual and/or Owners Manual as I would strongly suggest obtaining these and reading cover to cover..............there are a couple of guys on here with Fluid Drive Chryslers, Dodges & DeSotos and they will be able to give sound and correct advice..........I'd actually change the title of this thread to something that includes "Fluid Drive"  so they will see it..........again, welcome aboard.......Andy Douglas  

 

[bmcil26@aol.com]

Thank you so much.

[bmcil26@aol.com]

31 minutes ago, casper50 said:

Where are you checking fluid level?  As far as I know there's only 1 place to check the level of a fluid drive.

Hi, Finally figured out how to reply. I checked under the front mats on the tranny tunnel. As i recall there were two openings, maybe it was one. Thank you for your reply

 

[HotRodTractor]

I'm not totally familiar with your setup, but I don't believe the issue you are experiencing is with the Fluid Drive. The fluid drive is is just a viscous coupling between the engine and the clutch. The shifting mechanism you speak of sounds like you might have a "Presto Matic" transmission. This type of transmission operates off of electric solenoids and if the previous owner was swapping between 6V and 12V.... I would say you should start your investigation with your electrics.

 

Going from memory there is at least 2 solenoid cans on the transmission and there is an input on the carb. Under certain conditions (speed, RPM) the solenoids shift a gear, essentially turning a 2 speed transmission into a 4 speed transmission. I am sure that if you search on here, you'll find discussions of converting this setup to 12V, find a wiring diagram, and even finding "modern interpretations" of how this system works and how to make it work using just toggle switches to eliminate some of the system for troubleshooting purposes.

 

There was also about half a dozen different names this transmission setup had through the different Mopar branches, so keep in mind it might be listed under one of several different names.

[Plymouthy Adams]

also remember that your engine speed must drop to below X rpm for a clean smooth shift...could be just as simple as adjusting your base idle.....

[Doug&Deb]

Idle should be between 450-500 rpms. This tranny doesn’t usually respond well to a 6-12 conversion. How many miles are on the car? This is a robust driveline but it can wear out. Regarding the 6-12 conversion search this forum. Someone with a fluid drive has probably done this and can walk you through the process. Good luck.

[Greg51T&CWagon]

I'd try and locate a local cruise night or car club and quiz those guys about local mechanics. Make some friends there and you never know maybe someone will volunteer to help you learn the basics of taking care of your car and simple repair stuff. Good luck.

[keithb7]

The fluid drive is just the coupler between the engine and tranny. The actual tranny seems to be the problem here. 

 

As you drive the car a pump off the car’s driveline turns. It builds oil pressure as you speed up. This oil pressure is sitting there like a horse at the gate ready to go. You let your foot off the gas momentarily to initiate a gear shift. A switch closes on the carb linkage at the carb. The engine drops briefly to idle speed. This releases forward torque off the gears in the tranny. Then the hydraulic oil (10W engine oil) that is waiting under pressure makes a move. A spinning/rotating switch opens, it then causes solenoid to move. A check ball in a seat overcomes it’s spring pressure, by the oil pressure. The oil then quickly flows to a sealed cylinder with a piston. The oil pressure pushes that piston. This piston has a shift fork connected to it. It moves a clutch-gear sleeve on the main shaft inside the transmission. This is the actual shift that is grinding.

 

10W oil is needed here to flow properly and quickly. Engine idle speed needs to be properly set. Otherwise the torque load on the one-way ramp clutch on the tranny countershaft, does not allow the shaft to fully disengage. So it will sound like a gear grinding. If this gear is still partially engaged due to high engine rpm, gears clash. 

 

Start with checking your engine idle speed. Try lowering it. See what happens. Be sure you have 10W engine oil in the tranny. Not in the fluid drive. Beyond that, oil test pressure gauges may be required to test tranny pump pressure. 

 

Does anyone know a good mechanic in the Chicago area for the owner of this ‘49 Windsor? 

 

I’d get that car back to 6V the way it was designed to work. My ‘53 is all original and my 6V system works just fine. The Chrysler engineers were no dummies. 

Edited October 21, 2019 by keithb7

[HotRodTractor]

A very quick search for some links that may help in diagnosis:

 

http://p15-d24.com/topic/34065-fluid-drive-not-downshifting-what-to-check/

 

http://p15-d24.com/topic/41254-49-fluid-drive-advice-needed/

 

http://p15-d24.com/topic/16946-a-new-carb-question/

 

It seems to me there is enough information there to at least lead someone down the path of a diagnosis.

 

 

[greg g]

Put the tools down and back away from the Chrysler!  Do go to the all par website, search transmissions and read up on the my semi automatic, as mentioned the fluid drive and the transmission are two distinct assemblies with two separate jobs.  The m6 is pretty bullet proof with most faults external and related to electrical connections and idle speed.  If yours is up shifting and down shifting except for the noise, it's probably transmission lubricant being low.  Not fluid drive fluid.  Now go to the Imperial club website and look up m6 semi auto in the repair section there.  Chances are you can sort this yourself without engaging a mechanic who knows no more about the function of the units than you do.  I wouldn't mess with anything or let a modern technology mess with anything until your reading assignments are complete. 

Edited October 21, 2019 by greg g

[Doug&Deb]

I completely agree with Greg g. You can troubleshoot this .

[Andydodge]

BMCIL..........I thought the change in the thread title might work, it acted like bait......lol........hang in there these guys will get you right............BTW....got a pic of the car.......we all love pics.......andyd 

[dpollo]

the electrics on the  transmission serve only to drop the oil pressure to allow a downshift.  Of course they were designed to work on 6 volts but this has nothing to do with your grinding noise.  Make sure the transmission has an oil equivalent to SAE 10 .    You were correct in checking the fluid drive oil level but that unit has little if anything to do with the  shifting.

[MarcDeSoto]

Here is a link to the original Mopar Master Tech film strips and M.T.S.C. booklets that were given to dealer mechanics when they saw the filmstrips at work.  They saw one filmstrip a month.  There are two filmstrips for the M-6 transmission from 1949-52, and there are two filmstrips for the earlier 46-48 M-5 transmission.  Both transmissions are very similar, just some differences in the electrical system.  These are found at the MyMopar website, and I'm going to give you a link because it's very hard to go to Youtube and do a search.  It doesn't work that way very well.  When you click the link, go to the 1949 year and look for the 2-11 and 2-12 volumes.  Click on the tv for the filmstrip and click on the booklet for the booklet.  

 

http://www.mymopar.com/index.php?pid=406

 

[keithb7]

This is all great info folks. It’s clear that we are passionate about maintaining and repairing our old Mopars. The responses show how we’re ready to dig in and get things done.  

 

To the original poster, are you interested in digging in? Are you interested in learning how the  transmission systems work in your ‘49? Are you considering trying to fix it yourself with our guidance? Or are you still looking for a competent mechanic in the Chicago area? Seems like that may be hard to find.